Yesterday, the regulator called for “sweeping reform” of the energy market and indicated that utility companies were confusing consumers who were unable to easily compare tariffs and find the best deal.

Mr Marlee said there was “broad acknowledgement” that the energy market needed to work better for consumers. As part of this Ofgem will be forcing energy companies to auction off up to 20% of generation to try and enable smaller competitors to enter the market.

“I wholeheartedly welcome the regulator Ofgem’s announcements today,” Mr Huhne said. “With households and businesses facing rising energy prices, I want to see more clarity in billing to help consumers shop around and switch to the best deal. People can save hundreds of pounds a year by shopping around right now.”

Earlier this month, Scottish Power became the first major energy company to announce another round of bill increases.

The firm said it was increasing the cost of gas by 19% and the cost of electricity by 10%. Other firms are expected to follow suit in the coming months.

Yesterday, Ofgem also announced that it had launched an investigation into whether Scottish Power had issued “potentially misleading marketing”.

Alistair Buchanan, the chief executive of the regulator, said: “Our new investigation into potentially misleading marketing by Scottish Power is a further strong signal to the industry that we wish to see a sea change in the way customers are treated. Companies that fail to play it straight with consumers need to understand that they risk facing enforcement action.”

The price rises are leading a growing number of consumers to take out fixed price utility deals. These allow people to fix the price of their energy bills – at a higher price than the current price – for up to five years.

According to USwitch, a website, almost six in ten households have taken out the schemes in the past year.

The Bank of England has blamed rising energy bills for rocketing levels of inflation. Most households have seen bills double in the past five years.